1. Technical Field
The present invention relates to a nitride semiconductor light emitting device and a method of fabricating the same.
2. Related Art
Nitride semiconductor light emitting devices have conventionally been disclosed in which n-type semiconductor layers are grown while silicon (Si) serving as an n-type impurity is added thereto. In more detail, the n-type semiconductor layer in one of the conventional nitride semiconductor light emitting devices is formed by substituting Si for gallium (Ga) in the semiconductor layer such as gallium nitride (GaN) layer. Si is more easily controllable than elements of other n-type impurities when added to the n-type semiconductor layer. Accordingly, in the nitride semiconductor light emitting devices, an n-type semiconductor layer having desired characteristics can easily be fabricated by growing the n-type semiconductor layer while Si as an n-type impurity is added to the n-type semiconductor layer.
Thus, in the conventional nitride semiconductor light emitting device as described above, Si is substituted for Ga in GaN while Si is added to the n-type semiconductor layer. Si has a smaller atomic radius than Ga. Accordingly, when grown while a large amount of Si is added as the n-type impurity for the purpose of reduction in a device resistance, the n-type semiconductor layer causes tensile strain, resulting in occurrence of cracks. More specifically, since the above-described conventional semiconductor light emitting device is likely to cause cracks, there is a possibility that the device with good quality cannot be obtained.